Skin Preparation For External Use

ABSTRACT

The present invention provides an external composition for skin that has excellent effects in improving elasticity and alleviating wrinkles while moisturizing the skin, has good spreadability on the skin, and has no stickiness. The external composition for skin of the present invention is characterized by comprising: (A) an acrylic polymer comprising the following monomers (a1), (a2), and (a3) as constituent monomers: (a1) acrylic acid or methacrylic acid; (a2) an alkyl acrylate or alkyl methacrylate; and (a3) an ester between acrylic acid or methacrylic acid and polyoxyethylene alkyl ether; and (B) a cross-linked polyamino acid or its salt. In the external composition for skin of the present invention, it is preferable that (A) is 0.01 to 10.0 weight % as a polymer, and (B) is 0.0001 to 5.0 weight % as a polymer.

FIELD OF THE INVENTION

The present invention relates to an external composition for skin, andin particular, to an external composition for skin containing an acrylicpolymer.

BACKGROUND OF THE INVENTION

Conventionally, moisturizing agents and film-forming agents are blendedto an external composition for skin for the purpose of improvingelasticity and alleviating wrinkles of skin. The moisturizing agentsupplies water to surface and interior of skin and it provideselasticity to skin. However, unless a relatively large amount isblended, it is not effective and it may cause heavy sticky feeling.

On the other hand, the film-forming agent stretches fine wrinkles withthe force of contraction, which is generated during film formation,provides elasticity to skin, and temporarily removes wrinkles. However,there are problems in that the adhesion to skin is weak and use may beuncomfortable.

In order to improve elasticity and alleviating wrinkles and to achievegood moisturizing, cosmetics containing combination of thickeners suchas carboxyvinyl polymers, xanthan gum and hydroxyethyl cellulose, andmoisturizing agents such as glycerin have been disclosed (JapanesePatent Application Laid-Open (Kokai) NO. 2000-143477, and JapanesePatent Application Laid-Open (Kokai) NO. 2004-149463).

However, the above-described cosmetics had problems in that thespreadability on skin was poor, or they became sticky after application.In addition, good moisturizing effect could not be achieved, and theeffect of improving elasticity and alleviating wrinkles was notsufficient.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-describedproblems of the prior art. An object of the present invention is toprovide an external composition for skin that has excellent effects inimproving elasticity and alleviating wrinkles while moisturizing theskin, has good spreadability on the skin, and has no stickiness.

In view of the above circumstances, the present inventors havediligently carried out an investigation. As a result, the inventors havefound that the following external composition for skin can be prepared.This external composition for skin has excellent effects in improvingelasticity and alleviating wrinkles while moisturizing the skin, hasgood spreadability on the skin, and has no stickiness. The presentinvention was achieved by using a specific acrylic polymer as athickener and by blending a cross-linked polyamino acid.

The external composition for skin of the present invention ischaracterized by comprising:

(A) an acrylic polymer comprising the following monomers (a1), (a2) and(a3) as constituent monomers:

(a1) acrylic acid or methacrylic acid;

(a2) an alkyl acrylate or alkyl methacrylate; and

(a3) an ester between acrylic acid or methacrylic acid andpolyoxyethylene alkyl ether; and

(B) a cross-linked polyamino acid or its salt.

It is suitable that component (A) is one or more selected fromacrylate/ceteth-20 methacrylate copolymer, acrylate/steareth-50methacrylate copolymer, acrylate/steareth-20 methacrylate copolymer, andacrylate/beheneth-25 methacrylate copolymer.

It is suitable that component (B) is one or more selected fromcross-linked poly-gamma-glutamic acid, cross-linked poly aspartic acidand also salts thereof.

In the above-mentioned external composition for skin of the presentinvention, it is preferable that the blending quantity of the component(A) is 0.01 to 10.0 weight % as a polymer, and the blending quantity ofthe component (B) is 0.0001 to 5.0 weight % as a polymer.

In the above-mentioned external composition for skin, it is preferablethat a water-soluble drug is further comprised.

In the above-mentioned external composition for skin, it is preferablethat pH of the composition is 6.0 to 7.5.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the result of elasticity-improving test in this invention.

FIG. 2 shows the result of wrinkle-alleviating test in this invention.

FIG. 3 shows the result of moisturizing test in this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The working mode of this invention is explained below.

<Component (A)>

The acrylic polymer used in this invention is a copolymer of monomers ofthe following (a1) to (a3):

(a1) acrylic acid or methacrylic acid;(a2) an alkyl acrylate or alkyl methacrylate; and(a3) an ester between acrylic acid or methacrylic acid andpolyoxyethylene alkyl ether.

These are, for example, acrylates/ceteth-20 methacrylate copolymer,acrylates/steareth-50 methacrylate copolymer, acrylates/steareth-20methacrylate copolymer, acrylates/beheneth-25 methacrylate copolymer,etc., which are listed on the INCI (International Cosmetic IngredientDictionary). These copolymers are commercially available in waterdispersion (polymer emulsion) under the product names Aculyn 22, Aculyn28, etc. (Rohm & Haas).

Among all the acrylic polymers of this invention, especially ACULYN 22(acrylate/steareth-20 methacrylate copolymer) is desirable, because itis not sticky to the touch. ACULYN 22 is a water dispersion of copolymerof

(a1) methacrylic acid,(a2) ethyl acrylate, and(a3) ester between methacrylic acid and polyoxyethylene (20) stearylether.

Water dispersions of the above acrylic polymers are diluted with wateretc. as necessary, and neutralized by the addition of alkali in order tothicken the dispersions. Therefore it is suitable that pH of theexternal composition for skin in this invention is within the range of 6to 7.5. As an alkali agent for neutralization, not restrictedespecially, inorganic bases such as sodium hydroxide, potassiumhydroxide and so on, organic base such as triethanolamine, isopropanolamine, basic amino acid and so on can be used.

In the external composition for skin of the present invention, theblending quantity of the above component (A) is preferably from 0.01 to10.0 weight % as a polymer, more preferably from 0.03 to 9.0 weight %,further more preferably from 0.05 to 5.0 weight %. If the quantity isless than 0.01 weight %, the effect of improving elasticity andalleviating wrinkles cannot be sufficiently achieved. If the quantityexceeds 10.0 weight %, the utilization is impaired.

The thickening action of the above component (A) is mainly due to thehydrophobic action of the hanging alkyl group on the tip of the POEchain and the positive charge repulsion by the carboxyl group.

<Component (B)>

The cross-linked polyamino acid has a structure in which a part of thepolyamino acid is cross-linked. The basic skeleton of the cross-linkedpolyamino acid consists of polypeptides formed by condensation of aminoacids.

For the embodiment of amino acid, for example, 20 kinds of amino acidsshown in the following (i) to (iv) can be listed.

(i) Nonpolar amino acid (in other words that has hydrophobic group):alanine, valine, leucine, isoleucine, methionine, tryptophan,phenylalanine, proline.(ii) Polar amino acid without electric charge: glycine, serine,threonine, cysteine, tyrosine, asparagine, glutamine.(iii) Amino acid with positive charge group: lysine, histidine,arginine.(iv) Amino acid with negative charge group: aspartic acid, glutamicacid.

For the other embodiment of amino acid, for example, L-ornithine, aminoacid and also amino acid derivatives such as alpha-amino acid,beta-alanine, gamma-aminobutyric acid, neutral amino acid, acidic aminoacid, ohm-ester of acidic amino acid, basic amino acid, N-substitutionproduct of basic amino acid, aspartic acid-L-phenylalanine dimer(aspartame) and so on, and amino sulfonic acid such as L-cysteic acidand so on can be listed. α-Amino acids can be either optically activeisomers (L-isomer, D-isomer) or racemates.

Although a cross-linked polyamino acid used in the present invention canbe either a homopolymer or copolymer, preferably a homopolymer is used.Among all, if we consider the benefits of non-stickiness and a goodmoisturizing effect, a cross-linked polyamino acid should preferablyhave polyaspartic acid or poly-γ-glutamic acid as the basic skeleton. Ahomopolymer of poly-γ-glutamic acid is especially desirable.

There is no restriction for the type of copolymer, and any one of theblock copolymer, random copolymer, graft copolymer, etc. can be adopted.As embodiments of copolymer component (monomer component other thanamino acid), for example, amino carboxylic acid, amino sulfonic acid,amino phosphonic acid, hydroxy carboxylic acid, mercapto carboxylicacid, mercapto sulfonic acid, mercapto phosphonic acid, and so on can belisted, but not restricted to them.

The side chain of the cross-linked polyamino acid used in the presentinvention preferably has no substituents. If there is a substituent, itgenerates sticky feeling during use.

In the cross-linked polyamino acid of the present invention, there is nospecial restriction for the bond between the basic skeleton and thecross-linking sections. In the case of acidic polyamino acids, it isusually the amide bond, ester bond, or thioester bond.

The cross-linked polyamino acid of the present invention can be of asalt form. As counter ion of carboxyl group, alkali metal (Na, K etc.)salt, ammonium salt, amine salt and so on are listed. As a salt, sodiumsalt or potassium salt is desirable from a viewpoint of smell.

(Manufacturing Process of Cross-Linked Polyamino Acid)

There is no special restriction for the manufacturing process ofcross-linked polyamino acids. For example, they can be prepared bypublicly known methods described in Japanese Patent ApplicationLaid-Open (Kokai) NO. Hei 7-224163, Japanese Patent ApplicationLaid-Open (Kokai) NO. Hei 7-309943, Japanese Patent ApplicationLaid-Open (Kokai) NO. 2001-72764, Japanese Patent Application Laid-Open(Kokai) NO. 2003-12442, etc. Especially in the present invention,cross-linked poly-γ-glutamic acid obtained by radiation cross-linking,which is described in Japanese Patent Application Laid-Open (Kokai) NO.2003-12442, and the salt thereof is desirable from a viewpoint offeeling during use.

The concrete manufacturing process of cross-linked poly-gamma-glutamicacid by radiation-induced crosslinking is as follows.

1. Initially, the starting material poly-γ-glutamic acid is prepared.Poly-γ-glutamic acid can be prepared by various methods, for example,cultivation of microorganisms, namely cultivation of Bacillus subtilis,cultivation of genetically modified microorganisms, preparation withnatto, or chemical synthesis.

For the preparation of poly-γ-glutamic acid by the microorganismcultivation, any strain is usable so far as it can producepoly-γ-glutamic acid outside of the bacteria. In particular, bacterialspecies of the genus Bacillus are desirable. Specific examples areBacillus subtilis, Bacillus anthracis, Bacillus natto, and the like.Especially, poly-γ-glutamic acid, which is produced by microorganismssuch as Bacillus subtilis, with a molecular weight of more than severalmillions is desirable.

So far as they can produce poly-γ-glutamic acid, any strain, culturemedium, etc. can be used in the microorganism cultivation. For example,either a synthetic medium or natural medium can be used as a culturemedium so far as the medium contains an appropriate carbon source,nitrogen source, inorganics, and other nutrients. Amino acids to beadded include L-glutamic acid, aspartic acid, alanine, leucine,phenylalanine, histidine, etc., or salts thereof can be used.Preferably, L-glutamic acid is used from 2 to 12 weight %, and morepreferably from 3 to 10 weight %.

As carbon source, glucose, sucrose, citric acid, xylose and so on can beused, among them citric acid or glucose is desirable. As nitrogensource, organic nutrition resource such as peptone or yeast extract,inorganic nutrition resource such as ammonium sulfate and so on can beused. The cultivation is carried out by shaking cultivation, stirringcultivation, and the like under aerobic conditions. The culturetemperature is from 25 to 45° C., preferably from 30 to 40° C. The pHduring the cultivation is from 5 to 9, preferably from 6 to 8. The pHduring the cultivation is adjusted with sodium hydroxide, potassiumhydroxide, and the like.

The cultivation is usually carried out for 48 to 72 hours, and theproduced poly-γ-glutamic acid is accumulated outside of the bacteria.After the cultivation is completed, poly-γ-glutamic acid in the culturebroth can be collected by the conventional method. That is,poly-γ-glutamic acid can be collected by centrifuging, filtering with afilter aid or a fine pore filter to remove bacteria, and byultrafiltration. Then poly-γ-glutamic acid is precipitated by theaddition of 3 to 4 times of ethanol. The precipitate is dissolved inwater, insolubles are removed, and low molecular compounds are removedby dialysis or ultrafiltration etc. Poly-γ-glutamic acid can becollected by repeated reprecipitation by ethanol etc.

2. The above-described poly-γ-glutamic acid is dissolved in a solvent inthe concentration range of 2 to 20 weight %, preferably 5 to 15 weight%. The obtained solution is irradiated, and the formed cross-linkedcompound is separated and purified. As a solvent, acetone, methylacetate, ethyl acetate and so on are used in addition to water andalcohol, and among them water, methyl alcohol and ethyl alcohol aredesirable, especially water is desirable.

A radiation-permeable vessel such as a glass vial is used for a solutioncontaining dissolved poly-γ-glutamic acid. There is no restriction forthe type of radiation, for example, α-ray, β-ray, γ-ray, electron beam,neutron beam, or X-ray can be used. Preferably, the electron beam isused. The normal quantity of irradiated electron beam is preferably notless than 20 kGy. The irradiation time is preferably not less than 1second. If it is less than 1 second, the formation of the cross-linkedcompound may not be sufficient.

Subsequently, solid cross-linked poly-γ-glutamic acid is obtained byremoving the solvent. The cross-linked poly-γ-glutamic acid is colorlessand transparent, and it has excellent water-absorbing property andbiodegradability. Cross-linked poly-γ-glutamic acid obtained by theabove method may be granulated to a predetermined shape or shaped intoan undefined crushed form, spherical form, etc.

In the present invention, the blended amount of the above-describedcomponent (B) is, in terms of dry weight, 0.001 to 5.0 weight %,preferably 0.01 to 3.0 weight %, more preferably 0.2 to 3.0 weight %. Ifthe amount is less than 0.001 weight %, the moisturizing effect is notsufficient. If the content exceeds 5.0 weight %, not only themoisturizing effect is not enhanced but also the following problems arecreated. These problems include time-dependent instability of theexternal composition for skin, stickiness, and heaviness, which areencountered during use.

In the present invention, external composition for skin comprising theabove-described component (A) and component (B) are prepared. Thus,cosmetics that have no stickiness during use, good spreadability andadaptability to the skin, no stickiness after application, nice touch,excellent moist feeling, and excellent effects in improving elasticityand alleviating wrinkles can be obtained.

<Water-Soluble Drug>

In the present invention, if water-soluble drugs, with anti-agingeffects, such as thiotaurine, rose apple leaf extract, yeast extract, orrose extract are blended with the above-described component (A) andcomponent (B), these drugs can be effectively infiltrated into the skin.

Also, a whitening agent can be blended. For example, as ascorbic acidline whitening agent, inorganic salt esters of ascorbic acid such asL-ascorbic acid, L-ascorbyl monophosphate, L-ascorbyl-2-sulfate, anddl-alpha-tocopherol 2-L-ascorbyl diphosphate; monoalkyl esters ofascorbic acid such as L-ascorbyl monostearate, L-ascorbyl monopalmitate,and L-ascorbyl monooleate; diesters of ascorbic acid such as L-ascorbyldistearate, L-ascorbyl dipalmitate, and L-ascorbyl dioleate; triestersof ascorbic acid such as L-ascorbyl tristearate, L-ascorbyltripalmitate, and L-ascorbyl trioleate; ascorbic acid-2-glycosides suchas 2-O-α-D-glucopyranosyl-L-ascorbic acid and so on can be listed.

The above-listed ascorbic acid and its derivatives are often blended assalts. Alkali metal salts (Na salt, K salt, etc.), alkaline earth metalsalts (Ca salt, Mg salt, etc.), ammonium salts, alkanolamine salts,amino acid salts, etc. can be used, however, alkali metal salts arepreferable.

As an example of alkoxysalicylic acid line whitening agent, for example,the one described in Japanese Patent Application Laid-Open (Kokai) NO.Hei 6-40886 is raised. As embodiments of said whitening agent, 3-methoxysalicylic acid, 3-ethoxy salicylic acid, 4-methoxy salicylic acid,4-ethoxy salicylic acid, 4-propoxy salicylic acid, 4-isopripoxysalicylic acid, 4-buthoxy salicylic acid, 5-methoxy salicylic acid,5-ethoxy salicylic acid, 5-propoxy salicylic acid, and salts of them canbe listed. As salt, alkali metal salt (Na salt, K salt etc.), alkalineearth metal salt (Ca salt, Mg salt etc.), ammonium salt, alkanolaminesalt, amino acid salt and so on are raised, among them alkali metal saltis desirable.

When a salt-type whitening agent is used in the external composition forskin of the present invention, it can be blended as a salt form or itcan be neutralized with an alkaline agent in the composition. There isno restriction for alkaline agents used for the neutralization ofsalt-type whitening agents so far as they can form salts. For example,metal hydroxide such as sodium hydroxide, potassium hydroxide and so on;alkanolamine such as monoethanolamine, diethanolamine, triethanolamine;organic acid salt such as sodium citrate, potassium malate, sodiumlactate and so on; amino acid such as lysine and so on can be listed.Among them, alkali metal hydroxide such as sodium hydroxide or potassiumhydroxide is desirable.

In this invention, the stability of the above salt-type whitening agentis guaranteed, by adjusting pH of external composition for skin at therange of 6 to 7.5.

Also, various kinds of medicines such as amino acid such as glycine,alanine, valine, leucine, threonine, phenylalanine, tyrosine, asparticacid, asparagine, glutamine, taurine, arginine, histidine and so on andalso these alkali metal salts and hydrochlorides; acyl sarcosine acid(for example sodium lauroyl sarcosine), glutathione; organic acid suchas citric acid, malic acid, tartaric acid, lactic acid and so on;Vitamin A and also the derivatives; Vitamin B and the like such asvitamin B₆ hydrochloride, vitamin B₆ tripalmitate, vitamin B₆dioctanoate, vitamin B₂ and the derivatives, vitamin B₁₂, vitamins B₁₅and the derivatives and so on; Vitamin E and the like such asalpha-tocopherol, beta-tocopherol, gamma-tocopherol, vitamin E acetateand so on; Vitamin D and the like; the vitamins such as vitamin H,pantothenic acid, pantethine and so on; nicotinamide, benzyl nicotate,gamma-orizanol, allantoin, glycyrrhizinic acid (salt), glycyrrhetinicacid and the derivatives, hinokitiol,1-methyl-4-(1-hydroxy-1,5,5-trimethyl-4-pentenyl) cyclohex-1-ene,eucalyptol, thymol, inositol, saponins such as saikosaponin, carrotsaponin, sponge cucumber saponin, and soapberry saponin, pantothenylethyl ether, ethynyl estradiol, tranexamic acid, arbutins,cepharanthine, and placenta extract can be listed.

There is no restriction for water-soluble drugs used so far as they canbe usually blended in cosmetics. For example, angelica extract, gambirextract, althea extract, arnica extract, aloe extract, aloe veraextract, ginkgo extract, nettle extract, foeniculum extract, rose fruitextract, isodon japonicus extract, scutellaria root extract,phellodendron Bark extract, Coptis extract, Hypericum extract,Netherlands mustard extract, seaweed extract, Artemisiae Folium extract,brown alga extract, chamomile extract, wild oat extract, Artemisiacapillaris extract, gardenia extract, striped bamboo extract, sophoraroot extract, clematis extract, cranesbill extract, tea extract, burdockextract, rice bran extract, comfrey extract, cactus extract, salviaextract, hawthorn extract, rehmannia root extract, perilla extract,filipendula extract, paeonia lactiflora extract, houttuynia herbextract, tincture zingiberis, iris root extract, white birch extract,water-soluble lithospermum root extract, ivy extract, yarrow extract,peppermint extract, peepul extract, mallow extract, swertia japonicaextract, Mori Cortex extract, soybean extract, thymus extract, Thymusspecies extract, tea extract, clove extract, citrus unshiu peel extract,tincture capsici, Japanese angelica root extract, calendula extract,bitter orange peel extract, carrot extract, wild rose extract, parsleyextract, witch hazel extract, rose extract, loquat extract, grape leafextract, sponge cucumber extract, safflower extract, Typha angustataBory et Chaub extract, Paeonia Suffruticosa extract, hop extract,marmelo extract, marronnier extract, rosemary extract, balm mintextract, sweet clover extract, peach leaf extract, cornflower extract,saxifrage extract, eucalyptus extract, lily extract, coix extract,lavender extract, lemon extract, rosemary extract, Rome chamomileextract, burnet extract, kiwi extract, grape fruit extract, and royaljelly extract can be listed.

In the external composition for skin of this invention, even ifsurfactant is not blended, a sufficiently stable composition is formed.Nevertheless surfactant can be blended for the purpose of moreimprovement of stability of composition, or other purpose.

For example, nonionic surfactants such as sorbitan monolaurate, sorbitanmonopalmitate, sorbitan sesqui oleate, sorbitan trioleate,polyoxyethylene sorbitan monolaurate, polyoxyethylene glycol monooleate,polyoxyethylene alkyl ether, polyethylene glycol di-fatty acid ester,lauroyl diethanol amide, fatty acid dipropanol amide, maltitol hydroxyaliphatic ether, alkylated polysaccharide, alkyl glucoside, sugar ester,and polyether denatured silicone; cationic surfactants such asstearyltrimethylammonium chloride, benzalkonium chloride, and laurylamine oxide; anionic surfactants such as sodium palmitate, sodiumlaurate, sodium lauryl sulfate, potassium lauryl sulfate,triethanolamine alkylsulfate, acylmethyltaurine salt; ampholyticsurfactants and so on can be blended by properly selecting.

In addition to the above-described components, other components thatusually can be blended into the external use compositions such ascosmetics can be blended into the external composition for skin of thepresent invention so far as the desired effect of the present inventionis not interfered.

For example, hydrocarbons such as liquid paraffin, squalane, andvaseline; fats and oils such as macadamia nut oil, olive oil, andlanolin; waxes such as jojoba oil, carnauba wax, and candelilla wax;silicones such as dimethylpolysiloxane, and methyl phenyl siloxane;higher alcohols such as capryl alcohol, lauryl alcohol, myristylalcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, cholesterol,and phytosterol; higher fatty acids such as capric acid, myristic acid,palmitic acid, stearic acid, behenic acid, lanolin fatty acid, linoleicacid, and linolenic acid; moisturizing agents such as polyethyleneglycol, glycerol, 1,3-butylene glycol, erythritol, sorbitol, xylitol,maltitol, mucopolysaccharides, hyaluronic acid, chondroitin sulfate,chitin, and chitosan; lower alcohols such as ethanol; anti-oxidants suchas butyl hydroxy toluene, tocopherol, and phytin; antibacterial agentssuch as benzoic acid, salicylic acid, sorbic acid, paraoxy benzoic acidalkyl esters, and hexachlorophene; coating agents, oil gelling agents,metal oxides, organic ultraviolet absorbents, inorganic metal salts,organic metal salts, alcohols, chelate agents, pH modifiers,antiseptics, thickeners, drugs, coloring matters, perfumes, purifiedwater and so on can be blended in the external composition of thisinvention properly.

There is no special restriction for the application form of the externalcomposition for skin of the present invention, and any application formis allowed. For example, aqueous solution type, solubilization type,emulsification type, powder dispersion type, water-oil 2 layer type,water-oil-powder 3 layer type, oil/water (O/W) emulsification type,water/oil (W/O) emulsification type, gel, aerosol, mist and capsule canbe listed. Products can also be of any type so far as the type isconventionally used for external composition for skin. They are, forexample, facial cosmetics such as lotion, milky emulsion, cream, andpack; make-up cosmetics such as foundation, blusher, lipstick, eyeshadow, eye liner, mascara, and sunscreen; body cosmetics; fragrancecosmetics; skin cleansing cosmetics such as make-up cleanser, facecleanser, and body shampoo; hair care cosmetics such as hair rinse andshampoo; ointment; and bath preparation.

The present invention is further described in the following Examples,which are not intended to restrict the invention. An amount isrepresented as weight % unless otherwise specified.

<Activity of Improving Elasticity and Alleviating Wrinkles>

Each sample was applied to the faces of 10 professional panel members.Five hours after the application, the sensory evaluation was performedconcerning the effectiveness in improving elasticity and alleviatingwrinkles.

(Valuation Basis)

A: All 10 members answered that it was effective in improving elasticityand alleviating wrinkles.

B: 7 to 9 members answered that it was effective in improving elasticityand alleviating wrinkles.

C: 3 to 6 members answered that it was effective in improving elasticityand alleviating wrinkles.

D: 2 or less members answered that it was effective in improvingelasticity alleviating and wrinkles.

<Moisturizing Activity>

Each sample was applied to the faces of 10 professional panel members.The sensory evaluation was performed concerning the moist feeling(moisturizing effect) after the application.

(Valuation Basis)

A: All 10 members answered that it had moist feeling.

B: 7 to 9 members answered that it had moist feeling.

C: 3 to 6 members answered that it had moist feeling.

D: 2 or less members answered that it had moist feeling.

<Stickiness>

Each sample was applied to the faces of 10 professional panel members.The sensory evaluation was performed concerning the stickiness after theapplication.

(Valuation Basis)

A: All 10 members answered that it had no stickiness.

B: 7 to 9 members answered that it had no stickiness.

C: 3 to 6 members answered that it had no stickiness.

D: 2 or less members answered that it had no stickiness.

<Spreadability on Skin>

Each sample was applied to the faces of 10 professional panel members.The sensory evaluation was performed concerning the spreadability at theapplication.

(Valuation Basis)

A: All 10 members answered that it had easy spreadability and there wasa smooth feeling upon use.

B: 7 to 9 members answered that it had easy spreadability and there wasa smooth feeling upon use.

C: 3 to 6 members answered that it had easy spreadability and there wasa smooth feeling upon use.

D: 2 or less members answered that it had easy spreadability and therewas a smooth feeling upon use.

Manufacturing Example 1 Cross-Linked Poly-gamma-glutamic Acid

10 weight % aqueous solution of Meiji γ-PGA (poly-γ-glutamic acidmanufactured by Meiji Seika Kaisha, Ltd.) was placed in a glass tray.The solution was irradiated with a Cockcroft-Walton type electron beamirradiation device. The irradiation was performed from a distance of 10cm, at 2.5 kGy/1 sec, and for a total of 12 seconds so that the totalirradiation dose would be 30 kGy. The treated material was immersed inwater at 4° C. for 1 week to remove non-cross-linked poly-γ-glutamicacid. The swollen poly-γ-glutamic acid gel, by absorbing water, wasfiltered with an 80 mesh wire-mesh filter. Then the gel was freeze-driedto obtain cross-linked poly-γ-glutamic acid with a gelation rate of 91%.

Manufacturing Example 2 Cross-Linked Poly Aspartic Acid

Lysine methyl ester dihydrochloride (7.2 parts) and lysinemonohydrochloride (22.6 parts) were dissolved in distilled water (40parts). The solution was neutralized by adding sodium hydroxide (7.8parts) little by little to prepare a lysine aqueous solution. On theother hand, polysuccinimide (100 parts) with a weight-average molecularweight (Mw) of 96,000 was dissolved in DMF (400 parts) under nitrogenatmosphere. To this solution was added the aforementioned lysine aqueoussolution, and the mixture was stirred for 1 hour. The reaction wascontinued for 20 hours after the stirring was stopped. The reactant wastransferred to a mixer equipped with a stirrer with blades, and to themixer was added distilled water (400 parts) and methanol (400 parts),and the gel was chopped at 8000 rpm for 5 minutes. Then, a 27 weight %sodium hydroxide aqueous solution (129.7 parts) was dropwise addedduring a span of 2 hours, the stirring was continued for 2 hours, andthe mixture was neutralized with 7 weight % hydrochloric acid to pH 7.Subsequently, to the mixture was added methanol (300 parts), and theprecipitate was dried at 60° C. Cross-linked polyaspartic acid (143parts) was obtained by crushing the dried precipitate with a sample milluntil a particle diameter of less than 100 μm was reached.

Samples shown in the following Tables 1 and 2 were prepared, andevaluated by the above valuation basis.

TABLE 1 Test example 1-1 1-2 1-3 1-4 1-5 1-6 2-1 2-2 2-3 2-4 Components(1) Thickener Acrylic polymer of this invention (*1) (as polymer (30%))0.1 0.5 1.0 5.0 10.0 30.0 1.5 1.5 10.0 10.0 (0.03) (0.15) (0.3) (1.5)(3.0) (9.0) (0.15) (0.15) (3.0) (3.0) Carboxy vinyl polymer (*2) — — 0.1— — — 0.1 — 1.0 — Alkyl denaturated carboxy vinyl polymer (*3) — — — —0.1 — — — — — Xanthan gum — — — — — — — 0.1 — 1.0 (2) Cross-linkedpoly-γ-sodium glutamate (Trade name: gel protein A-8001, 2% polymer aq.solution, manufactured by Idemitsu Technofine Co.) 25.0 50.0 30.0 10.0 —50.0 — — — — (3) Cross-linked poly aspartic acid (Manufacturing example2) — — — — 2.5 — — — — — (4) Bio yeast extract (*4) — 0.1 0.05 0.2 0.010.3 0.1 0.1 0.05 0.05 (5) 1,3-Butylene glycol 8.0 8.0 8.0 8.0 8.0 8.08.0 8.0 8.0 8.0 (6) Paraben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.150.15 (7) EDTA-3Na 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 (8)Potassium hydroxide Proper quantity (9) Perfume Proper quantity (10) Water Remainder (11)  POE (10 mol) monooleate 1.0 1.0 1.0 1.0 1.0 1.01.0 1.0 1.0 1.0 (12)  Glycerol monostearate 1.0 1.0 1.0 1.0 1.0 1.0 1.01.0 1.0 1.0 (13)  Cetyl alcohol 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0(14)  Beeswax 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (15)  Vaseline 2.02.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 (16)  Squalane 6.0 6.0 6.0 6.0 6.06.0 6.0 6.0 6.0 6.0 (17)  Dimethylpolysiloxane (6 mPa · s) 2.0 2.0 2.02.0 2.0 2.0 2.0 2.0 2.0 2.0 Activity of improving elasticity andalleviating wrinkles A A A A B A B C B C Moisturizing activity (moistfeeling) A A A A B A C C C C Stickiness A A A B B A D D C CSpreadability on skin A A A A B A C D D D

TABLE 2 Test example 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 Components (1)Thickener Carboxy vinyl polymer (*2) 0.01 3.0 0.5 — — — — — Alkyldenaturated carboxy vinyl polymer (*3) — — 0.5 0.5 — — — — Xanthan gum —— — — 0.01 3.0 0.5 — Hydroxyethyl cellulose — — — — — — 0.5 0.5 (2)Cross-linked poly-γ-sodium glutamate (Trade name: gel protein A-8001, 2%polymer aq. solution, manufactured by Idemitsu Technofine Co.) 50.0 — —— 50.0 — — — (3) Cross-linked poly aspartic acid (Manufacturing example2) — — — 2.5 — — — 2.5 (4) Bio yeast extract (*4) — 0.2 0.3 0.01 — 0.20.3 0.01 (5) 1,3-Butylene glycol 8.0 8.0 8.0 8.0 8.0 8.0 8.0 8.0 (6)Paraben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 (7) EDTA-3Na 0.01 0.010.01 0.01 0.01 0.01 0.01 0.01 (8) Potassium hydroxide Proper quantity(9) Perfume Proper quantity (10)  water remainder (11) POE (10 mol)monooleate 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 (12)  Glycerol monostearate1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 (13)  Cetyl alcohol 1.0 1.0 1.0 1.0 1.01.0 1.0 1.0 (14)  Beeswax 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (15)  Vaseline2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 (16)  Squalane 6.0 6.0 6.0 6.0 6.0 6.06.0 6.0 (17)  Dimethylpolysiloxane (6 mPa · s) 2.0 2.0 2.0 2.0 2.0 2.02.0 2.0 Activity of improving elasticity and alleviating wrinkles D D CC D D C C Moisturizing activity (moist feeling) B D D C B D D CStickiness C C D B C D D D Spreadability on skin C C D C D D C C (*1)ACULYN 22 (polymer 30%)(manufactured by Rohm and Haas Co.) (*2)SYNTHALEN K(manufactured by 3V SIGMA Co.) (*3) PEMULEN TR-1(manufacturedby NOVEON Co.) (*4) Biodynes EMPP (manufactured by Arch Personal CareProducts L.P. Co.)

(Process)

A desired skin care cream was obtained by gradually adding the oil phaseof (11)-(17) to the aqueous phase of (1)-(10) while the aqueous phasewas being stirred with a dispersion mill.

In all examples in which acrylic polymers and cross-linked polyaminoacids of the present invention were used, excellent effects in improvingelasticity and alleviating wrinkles while moisturizing the skin wereattained. Non-stickiness and good spreadability on the skin were alsoattained (Test examples 1-1 to 1-6). On the contrary, in the examples inwhich only component (A) is used (Test examples 2-1 to 2-4), orconventional thickeners are used instead of component (A) (Test examples3-1 to 3-8), there were the following problems. The effect of improvingelasticity and alleviating wrinkles was not satisfactory, and themoisturizing effect was not sufficient. The spreadability on the skinwas also poor, and there was stickiness.

<Activity of Improving Elasticity and Alleviating Wrinkles>

The activity of improving elasticity and alleviating wrinkles was testedby measuring the below-described dynamic viscoelasticity.

(The Test Method of Dynamic Viscoelasticity)

The storage modulus (G′) and loss modulus (G″) were measured with acorn-and-plate rheometer from Paar Physica (MCR-30) in the frequencyrange of 0.1 to 100 (rad/sec) for the samples of the below-describedTest examples 4 to 6. The results are shown in FIG. 1.

Test example 4: 3.3% aqueous solution of acrylate/steareth-20methacrylate copolymer (trade name; ACULYN 22, manufactured by Rohm andHaas Co.) (polymer 1%). (pH is adjusted to 7 by potassium hydroxide).

Test example 5: 10% aqueous solution of cross-linked sodiumpoly-gamma-glutamic acid (trade name; gel protein A-8001, manufacturedby Idemitsu Technofine Co.) (polymer 0.2%)Test example 6: mixture of Test example 4 and Test example 5 (1:1).

As shown in FIG. 1, the elastic modulus for the case in which component(A) and component (B) combined (Test example 6) were synergisticallylarger than those for independent individual cases (Test examples 4 and5). Therefore, the excellent activity of improving elasticity of thecomposition in this invention was confirmed by measuring dynamicviscoelasticity.

As an additional experiment, 1 g sample of Test example 6 was dropped ona 3 cm square vitro skin (artificial skin) that had 76 μm deep sulcuscutis. The vitro skin was allowed to stand for 24 hours at 25° C. under50% RH. Then, the observation was conducted with a confocal microscope(HD100D) from Laser Tech.

As shown in FIG. 2, the case in which component (A) and component (B)were combined had decreased skin unevenness even one day afterapplication. Thus, it was confirmed that the external composition forskin of the present invention had an excellent effect of alleviatingwrinkles.

<Moisturizing Activity>

10 μl samples of Test examples 4-6, 10 μl of water, and 10 μl of 5%glycerin aqueous solution were dropped on respective filter papers of 2cm square. The weight change of each filter paper was measured every 5minutes at 25° C. under 50% RH. The value n in (nX+m), which was derivedby the least squares method applied for the results, was defined as themoisture evaporation rate constant. The average of three values for eachsample was plotted as the absolute value. The lower the moistureevaporation rate constant, the more moisturizing effect it has. Theresults are shown in FIG. 3.

As shown in FIG. 3, the moisturizing effect for the case in whichcomponent (A) and component (B) were combined (Test example 6) wasdrastically better than that for independent individual cases (Testexamples 4 and 5). Even when compared with the conventional moisturizingagent glycerin, Test example 6 had a significantly higher moisturizingeffect. Therefore, the excellent moisturizing activity of thecomposition in this invention was confirmed by measuring moistureevaporation rate constant.

<Skin cream> (Blending components) (weight %)  (1) 1,3-Butylene glycol5.0  (2) (Sodium acrylate/acryloyl dimethyl 1.0 taurine) copolymer(Trade name: SIMULGEL EG, manufactured by SEPIC Co.)  (3) Cross-linkedpoly-gammaglutamic acid 3.0 (Manufacturing example 1)  (4) Polyethyleneglycol (40E.O.) 1.5 monostearate (Trade name; NIKKOL MYS-40V,manufactured by Nikko chemicals Co.)  (5) Glyceryl monostearate (self2.5 emulsion type) (Trade name: NIKKOL MGS-ASE, manufactured by Nikkochemicals Co.)  (6) Hydrogenated poly isobutene 5.0  (7) Meadowfoam oil5.0  (8) Decamethyl cyclopentasiloxane 3.0  (9) Stearyl alcohol 0.8 (10)Behenyl alcohol 1.5 (11) Cetanol 4.0 (12) Microcrystalline wax 2.0 (13)Acrylate/beheneth-25 methacrylate copolymer 3.0 (Tradename: ACULYN 28,manufactured by Rohm and Haas Co.) (14) Potassium hydroxide 0.1 (15)Paraben proper quantity (16) Edetic salt proper quantity (17) Dibutylhydroxytoluene proper quantity (18) Perfume proper quantity (19)Purified water remainder

(Process)

Components (1)-(3), (13)-(17), and (19) were evenly mixed and dissolved,and this water phase was warmed to 70° C. Components (4)-(12) and (18)were dissolved by heating to 70° C. to form uniform oil phase. The oilphase was gradually added to the water phase, and the mixture wasemulsified by a homo mixer. Subsequently, the emulsion was cooled with aheat exchanger, and the desired cream was obtained. The pH of obtainedskin care cream was 7.0.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Skin care milky lotion> (Blending components) (weight %)  (1)1,3-Butylene glycol 4.0  (2) Dynamite glycerin 7.0  (3) Polyethyleneglycol 1500 1.5  (4) Polyethylene glycol 20,000 1.0  (5) Xylitol 1.0 (6) Acetylated hyaluronic acid 0.01  (7) Carboxyvinyl polymer 0.14  (8)Xanthan gum 0.05  (9) Sodium hydroxide 0.2 (10) Acrylate/steareth-20methacrylate copolymer 1.0 (Trade name: ACULYN 22 (polymer 30%),manufactured by Rohm and Haas Co.) (11) Cross-linked poly-gamma-glutamicacid 1.0 (Manufacturing example 1) (12) Polyethylene glycol-60 glycerylisostearate 1.2 (Trade name: EMALEX GWIS-160, manufactured by Japaneseemulsion Co.) (13) Polyethylene glycol-5 glyceryl stearate 0.5 (Tradename: EMALEX GM-5, manufactured by Japanese emulsion Co.) (14) Stearicacid 0.45 (15) Myristic acid 0.15 (16) Hydrogenated palm oil 2.0 (17)Squalane 1.0 (18) Pentaerythritol tetra-2-ethyl hexanoate 4.5 (19)Dimethylpolysiloxane (6 mPa s) 2.0 (20) Rosa Roxburghii Extract 0.02(21) L-serine 0.01 (22) Trimethyl glycine 1.0 (23) Zingiber AromaticusExtract 0.3 (24) Tranexamic acid 2.0 (25) Vitamins-E acetate 0.05 (26)Sodium hexametaphosphate (first class 0.01 grade chemical) (27) Ethylparaben 0.23 (28) Butyl paraben 0.1 (29) Iron oxide proper quantity (30)Paraben proper quantity (31) Perfume proper quantity (32) Purified waterremainder

(Process)

Components (1)-(11), (20)-(30), and (32) were evenly mixed anddissolved, and this water phase was warmed to 70° C. Components(12)-(19) and (31) were dissolved by heating to 70° C. to form uniformoil phase. The oil phase was gradually added to the water phase, and themixture was emulsified by a homo mixer. Subsequently, the emulsion wascooled with a heat exchanger, and the desired skin care milky lotion wasobtained. The pH of obtained skin care milky lotion was 6.5.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Skin care cream> (Blending components) (weight %)  (1) Stearic acid 8.0 (2) Stearyl acohol 4.0  (3) Butyl stearate 6.0  (4) Propylene glycol5.0  (5) Cross-linked poly-gamma-glutamic acid 10.0 (Trade name; gelprotein A-8001)  (6) Glycerol monostearate 2.0  (7) Potassium hydroxide0.4  (8) Acrylate/beheneth-20 methacrylate copolymer 1.5 (Trade name;ACULYN 22 (polymer 30%), manufactured by Rohm and Haas Co.)  (9) Methylparaben 0.15 (10) Butyl hydroxy toluene proper quantity (11) Perfumeproper quantity (12) Purified water remainder (13) L-ascorbic acid 1.0

(Process)

Components (4), (5), (7), (8), (9), and (13) were added to component(12) and warmed to 70° C. Components (1)-(3), (6), (10), and (11) weredissolved by heating to 70° C. and added to the above water phase. Thenpreliminary emulsification was carried out. After emulsified particleswere homogenized with a homo mixer, the skin care cream was obtained byaeration, filtration, and cooling. The pH of obtained skin care creamwas 6.3.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Skin care milky lotion> (Blending components) (weight %)  (1) Stearicacid 2.0  (2) Cetyl alcohol 1.0  (3) Vaseline 4.0  (4) Squalane 5.0  (5)Glycerol tri-2-ethyl hexanoate 2.0  (6) Sorbitan monooleate 2.0  (7)Dipropylene glycol 5.0  (8) Polyethylene glycol 1500 3.0  (9)Triethanolamine 1.0 (10) Cross-linked sodium poly-gamma-glutamate 5.0(Trade name: gel protein A-8001, manufactured by Idemitsu TechnofineCo.) (11) Ethyl paraben 0.2 (12) Perfume proper quantity (13) Purifiedwater remainder (14) Acrylate/beheneth-25 methacrylate copolymer 1.0(Trade name; ACULYN 28 (polymer 20%), manufactured by Rohm and Haas Co.)(15) Sodium hydroxide 0.1 (16) Rose fruit extract 0.2 (17) Scutellariabaicalensis extract 0.1

(Process)

Components (7), (8), (9), (10), (14) and (15)-(17) were added tocomponent (14) and warmed to 70° C. (water phase). Components (1)-(6),(11) and (12) were mixed and heated to 70° C. (oil phase). The oil phasewas added to the above water phase and preliminary emulsification wascarried out. After emulsified particles were homogenized with a homomixer, the skin care milky lotion was obtained by aeration, filtration,and cooling. The pH of obtained skin care milky lotion was 6.3.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Skin care milky lotion> (Blending components) (weight %)  (1) Cetylalcohol 1.0  (2) Beeswax 0.5  (3) Vaseline 2.0  (4) Squalane 6.0  (5)Dimethylpolysiloxane 2.0  (6) Ethanol 5.0  (7) Glycerol 4.0  (8)1,3-Butylene glycol 4.0  (9) Cross-linked sodium poly-gamma-glutamate0.5 (Trade name; gel protein A-8001, manufactured by Idemitsu TechnofineCo.) (10) Polyoxyethylene (10) monooleate 1.0 (11) Glycerol monostearate1.0 (12) Quince seed extract (5% of aqueous solution) 5.0 (13)Phenoxyethanol 0.2 (14) Color agent (water-soluble dye) proper quantity(15) Perfume proper quantity (16) Purified water remainder (17)Acrylate/steareth-20 methacrylate copolymer 0.2 (Trade name; ACULYN 22(polymer 30%), manufactured by Rohm and Haas Co.) (18) Triethanolamine0.1 (19) Gambir extract 0.3

(Process)

Components (6)-(9), (12)-(14), (17), (18) and (19) were added tocomponent (16) and warmed to 70° C. (water phase). Components (1)-(5),(10), (11) and (15) were mixed and heated (oil phase). The oil phase wasadded to the above water phase and preliminary emulsification wascarried out. After emulsified particles were homogenized with a homomixer, the skin care milky lotion was obtained by aeration, filtration,and cooling. The pH of obtained skin care milky lotion was 6.8.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Lotion> (Blending components) (weight %)  (1) 1,3-Butylene glycol 6.0 (2) Glycerol 4.0  (3) Oleyl alcohol 0.1  (4) Polyoxyethylene (20)sorbitan monolaurate 0.5 ester  (5) Polyoxyethylene (15) lauryl alcoholether 0.5  (6) Ethanol 10.0  (7) Cross-linked sodiumpoly-gamma-glutamate 1.0 (Trade name; gel protein A-8001, manufacturedby Idemitsu Technofine Co.)  (8) Perfume proper quantity  (9) Coloragent (water-soluble dye) proper quantity (10) Methyl paraben 0.2 (11)Fading inhibitor (dimorpholino pyridazinone) proper quantity (12) Sodiumcitrate 0.04 (13) Citric acid 0.06 (14) Acrylate/beheneth-25methacrylate copolymer 0.1 (Trade name; ACULYN 28, manufactured by Rohmand Haas Co.) (15) Sodium hydroxide 0.3 (16) Purified water remainder(17) 2-O-alpha-D-glucopyranosyl-L-ascorbic acid 2.0

(Process)

Components (1), (2), (7), (9), (11)-(15), and (17) were dissolved in(16) at room temperature to obtain a water phase. Components (3)-(5),(8), and (10) were dissolved in (6), and this solution was mixed withthe above water phase and solubilized. Thus, the desired lotion wasobtained. The pH of obtained lotion was 6.7.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Microemulsion type lotion> (Blending components) (weight %)  (1)1,3-Butylene glycol 6.0  (2) Glycerin 5.0  (3) Polyethylene glycol 40003.0  (4) Cross-linked sodium poly-gamma-glutamate 3.0 (Trade name; gelprotein A-8001, manufactured by Idemitsu Technofine Co.)  (5)Acrylate/steareth-20 methacrylate copolymer 0.5 (Trade name; ACULYN 22,manufactured by Rohm and Haas Co.)  (6) Potassium hydroxide 0.1  (7)Olive oil 0.5  (8) Polyoxyethylene (20) sorbitan monostearate 1.5  (9)Polyoxyethylene (5) oleyl alcohol ether 0.3 (10) Ethanol 10.0 (11)Perfume proper quantity (12) Color agent (water-soluble dye) properquantity (13) Methyl paraben 0.3 (14) Lactic acid 0.06 (15) Sodiumlactate 0.04 (16) Edetic salt proper quantity (17) Purified waterremainder (18) Rose extract 0.1

(Process)

Components (4), (5), (6) were dissolved in a portion of component (17)(a part of water phase). Subsequently, components (1)-(3), (12),(14)-(16), and (18) were added to the rest of component (17) anddissolved at room temperature (water phase). On the other hand,components (7)-(9), (11), and (13) were added to component (10) anddissolved at room temperature. This alcohol phase was added to the abovewater phase, and a microemulsion was prepared. To this microemulsion wasadded the first part of water phase, and thus the desired microemulsiontype lotion was obtained. The pH of obtained microemulsion type lotionwas 7.0.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

<Skin care cream> (Blending components) (weight %)  (1) Cetyl alcohol5.0  (2) Stearic acid 3.0  (3) Vaseline 5.0  (4) Squalane 10.0  (5)Glycerol tri 2-ethyl hexanoate 7.0  (6) Dipropylene glycol 5.0  (7)Glycerin 5.0  (8) Cross-linked sodium poly-gamma-glutamate 15.0 (Tradename; gel protein A-8001, manufactured by Idemitsu Technofine Co.)  (9)Propylene glycol monostearate 7.0 (10) Polyoxyethylene (20) cetylalcohol ether 3.0 (11) Triethanolamine 1.0 (12) Butyl paraben 0.15 (13)Butyl hydroxy toluene proper quantity (14) Perfume proper quantity (15)Purified water remainder (16) Acrylate/steareth-20 methacrylatecopolymer 2.0 (Trade name; ACULYN 22 (polymer 30%), manufactured by Rohmand Haas Co.) (17) Saxifraga extract 0.1 (18) Thymus extract 0.1 (19)Sodium hydroxide 0.1

(Process)

Components (6)-(8), (11), and (16)-(19) were added to component (15) andwarmed to 70° C. (water phase). Components (1)-(5), (10), (12), (13) and(14) were mixed and heated to 70° C. (oil phase). The oil phase wasadded to the above water phase and preliminary emulsification wascarried out. After emulsified particles were homogenized with a homomixer, the skin care cream was obtained by aeration, filtration, andcooling. The pH of obtained skin care cream was 6.2.

This article had excellent effects in improving elasticity andalleviating wrinkles while moisturizing the skin, had good spreadabilityon the skin, and had no stickiness.

The external composition for skin of this invention has excellenteffects in improving elasticity and alleviating wrinkles whilemoisturizing the skin, has good spreadability on the skin, and has nostickiness by using a specific acrylic polymer and a cross-linkedpolyamino acid.

1. An external composition for skin comprising: (A) an acrylic polymercomprising, as constituent monomers: (a1) acrylic acid or methacrylicacid; (a2) an alkyl acrylate or alkyl methacrylate; and (a3) an ester ofacrylic acid and a polyoxyethylene alkyl ether or an ester ofmethacrylic acid and a polyoxyethylene alkyl ether; and (B) across-linked polyamino acid or a cross-linked polyamino acid salt. 2.The external composition for skin according to claim 1, wherein saidcomponent (A) is one or more selected from acrylate/ceteth-20methacrylate copolymer, acrylate/steareth-50 methacrylate copolymer,acrylate/steareth-20 methacrylate copolymer, and acrylate/beheneth-25methacrylate copolymer.
 3. The external composition for skin of claim 1,wherein said component (B) is one or more selected from cross-linkedpoly-gamma-glutamic acid, cross-linked poly aspartic acid and saltsthereof.
 4. The external composition for skin of claim 1, wherein saidcomponent (A) is present in an amount of 0.01 to 10.0 weight % as apolymer, and said component (B) is present in an amount of 0.0001 to 5.0weight % as a polymer.
 5. The external composition for skin of claim 1,further comprising a water-soluble drug.
 6. The external composition forskin of claim 1, wherein the pH of the composition is 6.0 to 7.5.
 7. Theexternal composition for skin of claim 2, wherein said component (B) isone or more selected from cross-linked poly-gamma-glutamic acid,cross-linked poly aspartic acid and salts thereof.
 8. The externalcomposition for skin of claim 2, wherein said component (A) is presentin an amount of 0.01 to 10.0 weight % as a polymer, and said component(B) is present in an amount of 0.0001 to 5.0 weight % as a polymer. 9.The external composition for skin of claim 3, wherein said component (A)is present in an amount of 0.01 to 10.0 weight % as a polymer, and saidcomponent (B) is present in an amount of 0.0001 to 5.0 weight % as apolymer.
 10. The external composition for skin of claim 2, furthercomprising a water-soluble drug.
 11. The external composition for skinof claim 3, further comprising a water-soluble drug.
 12. The externalcomposition for skin of claim 4, further comprising a water-solubledrug.
 13. The external composition for skin of claim 2, wherein the pHof the composition is 6.0 to 7.5.
 14. The external composition for skinof claim 3, wherein the pH of the composition is 6.0 to 7.5.
 15. Theexternal composition for skin of claim 4, wherein the pH of thecomposition is 6.0 to 7.5.
 16. The external composition for skin ofclaim 5, wherein the pH of the composition is 6.0 to 7.5.